A Swedish guy you've probably never heard of has written 22 of the greatest pop hits in history

Max Martin has been brought into the limelight more and more over the past few years, but for a period of time, he was a mysterious force behind the world's biggest pop music hits. Martin, whose real name is Karl Martin Sandberg, has been writing and producing songs since the '90s, but music fans have only recently begun recognizing his name as a standard part of the pop zeitgeist.